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Mixed Use Question (Chapter 5)

J

jeffo

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Joined
Nov 12, 2021
Messages
24
Location
Texas
Hi,

Let me thank everyone in advance here, this forum is loaded with good advice so far.

To start with my building is Type II-B Non sprinkled. It is a metal warehouse with wood framed offices (about 15-20%).

My offices are used to do wholesale sales calls and engineering of wheels.

My storage is a majority alloy wheels stored in cardboard boxes. We do have a couple metal racks, but not many, and the usual crap such as brooms, some of my christmas decor...

So we are Mixed use. B of course for the interior offices. Then the warehouse with wheels in cardboard boxes, should this be S-1 or S-2 ? I see Metal and steel objects and autoshops in S-2, but see cardboard boxes in S-1.

Here is the kicker, which unless I am reading it incorrect S-1 requires no fire barrier or wall, where as S-2 does. How is S-1 (moderate) require no fire barrier, where as S-2 (low) requires two hour? I get this by referring to table 508.4

I read about this on another thread on a older code here, but still it seems screwy:

Storage occupancy: separation from other occupancies, and S-1 vs S-2 - NFPA (fire) Code Issues - Eng-Tips

There is something I don't understand with the IBC 2006, Table 508.3.3. This is kind of related to NFPA codes, so not out of line to post here.. An example: A s
www.eng-tips.com www.eng-tips.com
 
This seems like a good application for 508.3 Nonseparated Occupancies, unless the building area exceeds the allowable area of the most restrictive occupancy.
 
Hi, the city has us as Type IIB.

My question is why would they require us to have a fire barier/wall of 2 hours?

It does seem like we fall into 508.3

From my research this is what I show, I hope this is not too much:

SECTION 508 - MIXED USE AND OCCUPANCY

Each portion of a building shall be individually classified in accordance with Section 302.1 Where a building contains more than one occupancy group, the building or portion thereof shall comply with the applicable provisions of Section 508.2, 508.3 or 508.4, or a combination of these sections.

508.2 Accessory occupancies – Does not apply

508.3 Nonseparated occupancies – APPLIES

508.3.1-- Individually classified in accordance with Section 302.1

508.3.1-- Most restrictive provisions of Chapter 9 shall apply to the total nonseparated occupancy area.

Chapter 9

906.1 Fire extinguishers required on B and S – which we do have these (75ft per 906.3)

907.2.2 Group B. We do not meet the criteria needed for a manual Fire Alarm

508.3.2 Allowable building area and height. We are one story, and according to Type IIB- NS = max 23,000 per table 506.2 – which this would change as I do have access to calculate the sq footage per 506.2.2 referral to Equation 5-1

508.3.3 We do not fall into the exceptions on this. This states no separation is required.

508.4 Separated occupancies. – WHY IS THIS APPLIED TO US?
 
Is this another thread? I thought we solved this issue already. isn't your building 9,000 SF? your most restrictive occupancy is less SF than the allowable area so no separation is required.
 
"Hi, the city has us as Type IIB"

As mentioned, you best use FRT wood for the offices, if not, and there is a fire, the insurance company won't give a rip about what the City classified it at.
 
HI, honestly I do not know what the offices are made of, as it was built 30 years ago, but I am assuming it is not FRT.

The city will not return calls on exactly how they have classified us. My architect had me on the drawing as IIB.

It seems like as others have said with the wood it would put me in class V?

I wanted to expand my building to like 13-14000, so if I was class V and used 508.3 it seems like I would be SOL.
 
If you have 30 feet clear all around this building (measured perpendicular to the exterior wall), the allowable area for Type VB construction, B occupancy, non-sprinklered would be 15,750 with the frontage increase in 506.3. That’s more restrictive than S-2.
 
Hi,

So my architect got the below reply today. How does Chapter 9 bridge a nonseparated occupancy over to 508.4 which is separated occupancy? I read that statement meaning that the most restrictive provision of Ch.9 for B or S2 would apply, not that it jumps to Separated Occupancy. What am I missing here?


Spoke with xxxx by phone today (finally). Read through code with xxx. You are getting called out on Section 508.3.1 third sentence:
  • Nonseparated occupancies shall...In addition, the most restrictive provisions of chapter 9 that apply to the nonseparated occupancies shall apply to the total nonseparated occupancy area....
The inspector is using above code reference interpreting Table 508.4 occupancies B & S-2 in the 'most restrictive provision'. Therefore; requiring the 2-hour separation of unseparated occupancies sub classification 'NS' (non-sprinklered). I pointed out this table has been interpreted in both directions. Note: a city inspector can choose how to interpret the code.
 
You would pick the worst of the NS from T504.3 and .4 and T506.2 you would be good on height and area....Then you just have to look in 903 to see if you exceed a fire area requirement if you want to avoid sprinklers...Without looking....12,000 for S1 maybe? I don't think there is one for B
 
jeffo said:
Hi,

So my architect got the below reply today. How does Chapter 9 bridge a nonseparated occupancy over to 508.4 which is separated occupancy? I read that statement meaning that the most restrictive provision of Ch.9 for B or S2 would apply, not that it jumps to Separated Occupancy. What am I missing here?


Spoke with xxxx by phone today (finally). Read through code with xxx. You are getting called out on Section 508.3.1 third sentence:
  • Nonseparated occupancies shall...In addition, the most restrictive provisions of chapter 9 that apply to the nonseparated occupancies shall apply to the total nonseparated occupancy area....
The inspector is using above code reference interpreting Table 508.4 occupancies B & S-2 in the 'most restrictive provision'. Therefore; requiring the 2-hour separation of unseparated occupancies sub classification 'NS' (non-sprinklered). I pointed out this table has been interpreted in both directions. Note: a city inspector can choose how to interpret the code.
Click to expand...
The inspector is taking the rule on how to apply the code to nonseparated occupancies and using it to claim it causes a requirement for an occupancy separation?
 
So how if we are non separated do we get put into 504 which is separated? Is this just up to the discretion of the inspector?

Jay, I am not honestly sure how. Our architect was told the above, but honestly I do not see the path to applying that code -- but then again, I am not an architect or expert on the code, I just read it.
 
jeffo said:
Hi,

So my architect got the below reply today. How does Chapter 9 bridge a nonseparated occupancy over to 508.4 which is separated occupancy? I read that statement meaning that the most restrictive provision of Ch.9 for B or S2 would apply, not that it jumps to Separated Occupancy. What am I missing here?


Spoke with xxxx by phone today (finally). Read through code with xxx. You are getting called out on Section 508.3.1 third sentence:
  • Nonseparated occupancies shall...In addition, the most restrictive provisions of chapter 9 that apply to the nonseparated occupancies shall apply to the total nonseparated occupancy area....
The inspector is using above code reference interpreting Table 508.4 occupancies B & S-2 in the 'most restrictive provision'. Therefore; requiring the 2-hour separation of unseparated occupancies sub classification 'NS' (non-sprinklered). I pointed out this table has been interpreted in both directions. Note: a city inspector can choose how to interpret the code.
Click to expand...
I think we need more details here like square footage's of each of the existing occupancy and the size / occupancy of the addition you want to build. A floor plan would also be very helpful.
 
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